Swiatek leads Poland into BJK Cup Finals last eight
Iga Swiatek wrapped up a 2-0 victory for Poland over five-time champions Spain to seal their place in the last eight of the Billie Jean King Cup Finals in Malaga.
World number two Swiatek beat Spain's Paula Badosa 6-3 6-7 (6-8) 6-1 in the second singles match.
Magda Linette had earlier put Poland in front by beating Sara Sorribes Tormo 7-6 (8-6) 2-6 6-4 in a thriller lasting three hours and 51 minutes.
"I wouldn't say that I pushed us to the quarter-finals, because Magda pushed us to the quarter-finals, so we did it together," said five-time Grand Slam champion Swiatek.
"I'm glad that we won a match as Team Poland. I felt like it was my best match since the US Open.
"I knew that I could come back in the third set and try to win it for Poland."
The tie was initially due to take place on Wednesday but was postponed because of a severe weather alert in Malaga.
Poland have not won the BJK Cup in its 61-year history and this is the first time they have reached the quarter-finals in its current format.
They will play 11-time champions the Czech Republic in the last eight on Saturday.
Later on Friday, Great Britain sealed their place in the quarter-finals with victory over Germany. They will face 2023 winners Canada on Sunday.